A. F. Foerste — Fossil localities in the early Paleozoics. 439 



again found at various points along the line of outcrops extend- 

 ing from the road corner south of Sparta Junction (29) to a 

 point about half way between Andover and Tranquility 

 (45). These exposures are also sufficiently well located on the 

 accompanying map. But along this second line, fossils, ex- 

 cept Scolithus, are rare, and the decisive locality is the one 

 carrying Olenellus and other fossils at the strong bend in the 

 road southeast of Iliff's Fond, as the pond northeast of Long 

 Pond is called (35). At the various localities examined 

 Olenellus was found at 5, 6, 7, 8, 9, 11, 12, 14, 15, and 35. A 

 trilobitic fragment resembling Ptychoparia was found at 43. 

 Species of Hyolithes were also seen, one resembling H. 

 America?ius, at 11, and another resembling H. co?7immiis, at 

 14. Various forms of the burrowed tubes known as Scolithus 

 were very common at many localities ; they were found at 5, 

 8, 9, 11, 14, 15, 22 (rare), 30, 35 on the hillside between 35 

 and 36, 51, and in the reddish siliceous limestones, weathering 

 at times to shale, and in the intercalated sandstones at 48, 49, 

 and 50. 



Any one at all closely observant will notice at once that 

 even in this limited area the Scolithus burrows were not all 

 made by the same species of animal. In the fine grained 

 siliceous limestones near Wright's Pond, 48, 49, 50, the bur- 

 rows are narrower, usually 2 mm in diameter or less, and closer 

 together and reach a length of 60 mm , or more, and they are 

 nearly straight and vertical to the bedding. This form is also 

 found in rocks of similar lithological character in some of the 

 exposures between Andover and Hardistonville. It was evi- 

 dently a somewhat more gregarious species than the ordinary 

 form, and preferred muddy bottoms while the ordinary form 

 chose a sandy habitus. A second form resembles the ordinary 

 type in choosing a sandy bottom. It had perhaps slightly 

 larger burrows, about 3 mm in diameter, or at times a little 

 larger. Its chief distinction lies however in its burrowing 

 habit, which was not distinctly vertical but the burrows are 

 irregular in direction, as though the animal after having entered 

 the sandy bottom, extended its burrows in a more or less 

 irregularly horizontal direction. It may represent a totally 

 different class of animals from those of the vertically burrow- 

 ing forms. It has been seen only at 51, near Lock wood, but 

 there it is abundant. 



Lithologically the Olenellus Cambrian sandstone can be 

 traced into eastern Pennsylvania, its limited thickness and 

 constant characters throughout this extent with the knowledge 

 that the base of the Magnesian limestone series in New 

 Jersey at least is Cambrian, making it probable that all 

 hitherto called Potsdam in eastern Pennsylvania is now to 



